exam 3 pwrpt 1

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exam 3 pwrpt 1
2010-03-28 16:35:25

Terms and concepts from the first powerpoint for the third exam
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  1. Name the organ systems
    • nervous
    • endocrine
    • muscle
    • skeletal
    • reproductive
    • digestive
    • respiratory
    • cardiovascular
    • excretory
    • lymphatic
    • immune
    • skin
  2. Four basic tissue types
    • epithelial
    • connective
    • muscle
    • nerveous
  3. Epithelial tissue
    • sheets of densley packed and tightly connected cells that cover inner and outer body surfaces
    • some epithelial tissues have specialized functions: secretion, cilia, taste, smell, protective, absorptive, transport, boundaries
  4. Muscle Tissue
    • made of elongated cells capable of contracting and causing movement by sliding of protein filaments past each other
    • most abundant tissues in the body
    • three types: skeletal, cardiac, smooth
  5. skeletal muscle
    responsible for locomotion and other body movements (e.g. breathing, shivering
  6. cardiac muscle
    makes up the heart and is responsible for the heartbeat and blood flow
  7. smooth muscle
    involved in movement and generation of forces in internal organs (e.g. gut, blood vessels)
  8. Neural tissue
    comosed of neurons and glial cells
  9. neurons
    • extremely diverse in size and form
    • function by generating electrochemical signals in the form of nerve impulses, these impulses are conducted via long extensions to other parts of the body where they communicate (often via chemicals realesed at synapses) with other neurons, muscle cells, or secretory cells to contral activities of organ systems
  10. glial cells
    provide a number of support functions for neurons
  11. connective tissue
    • consists of cells embedded in an extracellular matrix that they secrete
    • an important component of the extracellular matrix is protein fibers (e.g. collagen, elastin, cartilage)
  12. collagen
    • most common protein fiber in connective tissue matrix
    • very strong fiber
    • very dense in tough tendons and ligaments
    • forms netlike framework for organs to give shape and strength
    • it has low density as loose strands whin it fills in between organs
  13. elastin
    • protein fibers that can be stretched to several times its resting length and then recoil
    • tissues that are regularly stretched, such as lung walls and artery walls have abundant elastin
  14. cartilage
    a network of collagen fibers embedded in a flexible matrix of proteins and carbs, chondrocytes secrete matrix
  15. extracellular matrix of bone
    hardened by the deposition of calcium phosphate
  16. Adipose tissue
    • a connective tissue that forms and stores droplets of lipids
    • adipose tissue serves as a fuel reserve and as a cushion to protect internal organs. Layers of adipose tissue under the skin help insulate against heat loss
  17. blood
    • a connective tissue made up of cells in a fluid extracellular matrix called blood plasma
    • plasma also contains an abundance of proteins
  18. organ
    a discrete structure that carries out a specific function in the body
  19. organ system
    a group of organs that function together
  20. conditions that can vary in TERRESTRIAL environments
    • temp
    • gas content
    • humidity
    • water
    • mineral availability
    • light
    • etc.
  21. conditions that can vary in AQUATIC environments
    • temp
    • gas content
    • salinity
    • pH
    • hydrostatic pressure
    • light
    • etc.
  22. eury-
    spp. that are extremely tolerant of a wide range for a particular parameter
  23. steno-
    spp. that are not very tolerant of range of a particular parameter
  24. conformers (poikilo-)
    species that match their internal environment (as regards to a particular parameter) to the external conditions
  25. regulators (homeo-)
    species that control their internal environment to a particular set-point for a given parameter even though the external environment varie
  26. homeostasis
    the maintenance of constant conditions in the internal environment of an organism
  27. internal environment
    • extracellular fluid
    • cells
  28. feedback information
    signals any discrepancy between the set point and the conditions present
  29. set point
    the particular desired conditoin level
  30. error signal
    the difference between the set point and the feedback information
  31. Negative feedback system
    control center compares magnitude of variable to the set point value, integrates the information, and controls the response of the effector system(s) which control the magnitude of the variables bringing it back to set-point
  32. effectors
    • cells, tissues and organs that respon to commans from regulatory systems
    • called controlled systems
  33. regulatory systems
    obtain, process, and integrate information, then issue commands to controlled systems, which effect change
  34. negative feedback
    imformation that couses a regulatory system to reduce or reverse a process
  35. positive feedback
    information that tells a regulatory system to amplify a response
  36. feedforward
    information signals the system to change the setpoint. May anticipate change
  37. What is the most important parameter controlling the ranges of organisms?
  38. affect of T on organisms
    high temp makes processes go faster (as long as T isn't high enough to kill the organism)
  39. Q10
    • the rate of reaction at a particular temperature (RT) divided by the rate of the reaction at a temperature 10ºC lower (RT-10)
    • most biological Q10 values are between 2 and 3
  40. metabolic compensation
    a biochemical adjustment of enzyme systems to counter the effects of temperature
  41. acclimatization
    natural adaption, ex. metabolic compensation
  42. homeotherms
    maintain a constant body temperature, freeing them from Q10 effects
  43. Poikilotherms
    body temperature changes when environmental temperature changes
  44. heterothem
    animals that regulate body temperature at a constant leve some of the time
  45. temporal heterothermy
    hibernating animals
  46. spatial heterothermy
    keep core T constant but allow the periphery to vary if necessary (most homeotherms)
  47. Ectotherms
    (most animals aside from mammals and birds) depend on external heat sources to maintain body temperature
  48. endotherms
    (all mammals and birds) regulate body temp by (1) generating metabolic heat and (2) preventing (controling) heat loss
  49. metabolic rates in response to temperature
    endotherms vs ectotherms
    • ectotherms: metabolism decreases as air temperature decreases
    • endotherm: metabolic rate increases as temperature decreases
  50. homeothermy
    Heat Loss = Heat gain
  51. modes of heat loss
    conduction convection, radiation, evaporation
  52. modes of heat gain
    conduction, convection, radiation, metabolism
  53. Conduction
    • takes place between two solids in contact with one another. Direct transfer of the kinetic energy of molecular motion
    • Rate depends on: temp gradient between the two (T1-T2); surface area in contact (A); coefficient of thermal conductivity (K, expression for the ease of heat flow in a material)

    Rate = KA(T1-T2)
  54. Convection
    • takes place between a solid and a fluid, or between two fluids
    • factors are same as conduction (K, T gradient, A)
    • K is greater for water than for air
  55. Radiation
    • any object above absolute zero loses heat via radiation
    • the intensity varies directly with the temperature of the radiating surface
    • the wavelength varies inversely with surface T
    • objects at physiological T's emit mostly in the middle and long infared
    • skin color doesnt matter much for the radiating surface but does matter for how much solar radiation is absorbed
  56. general mechanisms for control of body temperature
    • metabolic rate
    • evaporation
    • insulation (conduction, convection, radiation)
    • vascular control (conduction, convection, radiation)
    • behavior (postural changes, burows, huddling, choice of microhabitat)
  57. mechanisms for temp control WITH significant energy costs
    • metabolism
    • evaporation
    • some behaviors
  58. mechanisms for temp control WITHOUT significant energetic costs
    • insulation
    • vascular changes
    • some behaviors
  59. TNZ
    • thermal neutral zone
    • within this zone the animal uses non-energetically costly meant to control TB
  60. LCT
    • lower critical temperature
    • animal must increase metabolism to generate more heat
  61. UCT
    • upper critical temperature
    • the animal must use evaporative cooling to maintain TB constant
  62. adaptations to cold
    • decrease conductive, convective and radiation heat loss: insulation, blood flow, behavior, body shape
    • decrease evaporative heat loss
    • increase metabolic rate
  63. time scales
    • evolutionary
    • seasonal
    • immediate
  64. insulation
    • all time scales
    • fur, feathers, blubber
    • fur and feathers trap air (lo "K")
    • insulation lowers conductive, convective and radiative heat loss
    • better insulation lowers the LCT and decreases the slope of the MR vs TA line
  65. Vascular regulation of TB
    • peripheral vasoconstriction and dilation
    • heat exchangers
    • heat sinks (thermal windows)
  66. Hunting response
    blood flow to limbs is periodically opened and closed to control heat loss, but not allow hand T to drop too far
  67. Countercurrent heat exchangers
    veins run next to arteries so that the blood going to the core is not as cold and not as much heat is lost to the environment
  68. heat sinks
    lots of blood vessels near the skin
  69. behavioral adaptions to cold
    • postural (decrease SA/ Volume)
    • huddling
    • microhabitat selection: out of wind, sunny slope, burrow, subnivean (under snow)
    • burrowing in snow
  70. increase metabolic rate (heat production) in response to cold
    • increase activity
    • shivering
    • non-shivering thermogenesis: brown adipose tissue, other (thyroid hormone, etc.)
  71. brown adipose tissue (brown fat)
    • sole function is heat production
    • brown fat is commonly found in newborns, animals that hibernate, and many active mammals in winter
    • brown fat cells have the protein thermogenin
  72. thermogenin
    protein which uncouples proton movement from ATP production, so that no ATP produced, but heat is released
  73. Adjustments to high TB and TA
    • increase heat loss via conduction, convection and radiation: insulation changes, vascular, behavioral
    • metabolic rate
    • evaporative water loss
    • heat storage
  74. evaporative cooling
    • the major adaptation to hi TA and/or TB
    • problems: costs energy, water loss, loss of effectiveness at high humidity
    • sweating, panting
  75. heat storage
    • temporary increase in body T
    • heat exchangers cool blood perfusing the brain
    • found in numerous species especially those capable of long term running, not present in cheetah
  76. behavioral thermoregulation
    • some ectotherms can use behavior to regulate body temperature in the natural environment
    • behaviors include basking in the sun, seeking shade, burrowing, or orienting the body with respect to the sun
    • endotherms also use behavioral thermoregulation. Most animals select the best thermal environment whenever possible, for example by seeking shade, breezes, etc.
  77. marine iguana thermoregulation
    color change: darker to increase radiation gain, lighter to decrease radiation gain
  78. advantages of warm fish
    • increased swimming power and speed
    • faster digestion and absorption (permits smaller stomach, more muscle mass per body volume)
    • retina, visual predator
    • brain, faster neural processing
    • allows range expansion to cooler waters
  79. hypothalamus
    • the vertebrate thermostat
    • the temp of the hypothalamus itself is the major source of feedback information in many species
    • negative feedback system
  80. fever
    • a rise in body temperature in response to pyrogens, they cause a rise in the hypothalmic set point.
    • immune system cells called macrophages attack pyrogens and release interleukins, chemicals that signal other cells and trigger other responses, including release of protaglandins
  81. exogenous pyrogens
    come from foreign substances such as invading bacteria or viruses
  82. endogenous pyrogens
    produced by cells of the immune system
  83. interleukins
    raise hypothalamic set point
  84. adaptive hypothermia
    • animals can save energy by turning down the thermostat below normal
    • many animals use regulated hypothermia as a means of surviving periods of cold and food scarcity
  85. hibernation
    regulated hypothermia lasting days or weeks with drops with drops to very low temperatures
  86. daily torpor
    adaptive hypothermia that can drop body temp 10-20ºC and save considerable metabolic energy (hummingbirds)